During that time, as she didn't want to give up running, Yao had to get up at 5 am to train by herself before the busy working day started.

A month later, Yao realized that it was running that she was most passionate about and decided to become a full-time athlete, taking part in marathons and cross-country running competitions around the country, even though she had no coach and no sponsor.

At the end of 2016, she met Qi Min, another runner and coach from Southwest China's Yunnan province, at a competition and, the next year, Qi took Yao under his wing. After meticulous training scheduled by Qi, Yao's running performances started to improve and she began regularly appearing on podiums.

Her breakthrough year, however, was 2018. In January, she took part in the Hong Kong 100, a 100-km ultramarathon considered to be one of Asia's most competitive. She not only won the race, but also smashed the competition's female course record by 40 minutes.

"That was the competition that I gained wide attention in the ultra running field," Yao recalls.

In June, she participated in her first overseas competition, the 120-km Lavaredo Ultra Trail in Italy. Yao finished second. She built a big lead in the first half of the race, but was passed by another competitor on the final descent.

"I started losing my vision in the middle of the race and I could not see the surface of the trail clearly," Yao recalls.

Three months later, she produced a remarkable performance at the UTMB and produced a dominant win in 11 hours 57 minutes and 46 seconds, more than 30 minutes ahead of the second-placed runner.

"I was quite excited when crossing the finish line, because it proves that Chinese athletes can stand at the top of the podium in cross-country running," Yao says.

In 2019, she took part in the 170-km race at the UTMB, the longest distance of the event, for the first time with confidence and ambition.

The race, on a brutal course, started at 6 pm. After a night's running, when the sun came up, her vision began to blur, and she finally had to drop out of the race because of her physical condition.

Failing to complete the course at the 2019 UTMB hit Yao hard and it led to a temporary absence from cross-country running for Yao. "I was well-prepared and quite confident for the UTMB, and the withdrawing from the race hurt me so much that I decided to turn to marathons, to run in another way," she says.

Qi thought that Yao had run too fast during the first part of the competition, and her body was too exhausted, causing her vision to suffer.